308 BACTERIOLOGY FOR NURSES 



the active immunization resulting from the form of vaccination 

 introduced by Jenner. 



The origin of vaccination against smallpox is not definitely 

 known. The method of introducing the virus from a smallpox 

 patient into a healthy person through an abrasion of the skin 

 in order to produce a mild form of the disease and protection 

 against subsequent attacks was practiced by the Turks during the 

 eighteenth century. In 1778 Lady Mary Montagu, the wife of 

 the British Ambassador at Constantinople, observing this practice 

 among the Turks, had her own son and daughter inoculated and 

 by her influence was instrumental in introducing the practice in 

 Europe. The disease thus induced was generally but not always 

 mild. Occasionally a case of unexpected virulence developed which 

 proved fatal to the individual inoculated and a starting point of 

 infection among unprotected persons. 



Edward Jenner, a physician practising in Gloucestershire, 

 England, was much impressed with the popular belief that those 

 who contracted cowpox from an affected animal were immune 

 to subsequent infection from smallpox. He believed that a disease 

 occurring amongst horses, known as horsepox, manifested by an 

 inflammatory and ulcerative condition of the hocks, was transferred, 

 by the hands of men who dressed the sores, to the teats of the cows 

 later milked by them and gave rise to cowpox. From infected 

 cows other milkers contracted a mild form of the disease which 

 manifested itself in lesions similar to those in the cow ; namely, 

 slight fever, malaise, loss of appetite, and a local papular eruption, 

 later becoming pustular and finally drying up, leaving cicatrices 

 varying in depth and extent at their site. Fully convinced that 

 such an infection gave rise to immunity against smallpox Jenner 

 determined to make experimental tests. In May, 1796, heinoculated 

 a boy with lymph from a cowpox lesion on the hand of a dairymaid 

 and in July he inoculated the same boy with pus from a smallpox 

 patient without resulting infection. In 1798 he furnished addi- 

 tional proof of the protection afforded by vaccination with cowpox 

 virus by inoculating a child direct from the vesicle on the teat of 

 a cow and from the resulting lesion inoculating another child, and 



